The purpose of this shared instrumentation grant is to obtain funds to purchase a Confocal Laser Scan Microscope and to upgrade our existing IBAS image analysis system so that it can accept data from the confocal microscope, perform 3-dimensional reconstructions and quantitate morphological data. The acquisition of this instrument is part of our plan to develop a state-of-the-art microscopy facility at Cold Spring Harbor Laboratory. This instrumentation is currently needed by a group of 5 major users, and its use will expand in the future through minor and new users.